Many articles of wear benefit from traction elements. Such articles of wear come into contact with a surface or another item and benefit from the increased friction and stability provided by traction elements. Traction elements typically form a portion of the ground-contact surface of the article of wear. Many traction elements form protrusions that extend away from the surface of the article of wear toward the ground or surface that contacts the article of wear. Some traction elements are shaped to pierce the ground or surface when the article of wear comes into contact with the ground or surface. Other traction elements are shaped or have characteristics that engage with the ground in a way that increases the friction between the article of wear and the surface that it contacts. Such traction elements increase lateral stability between the traction element and the ground or surface and reduce the risk that the article of wear will slide or slip when it contacts the ground or surface.
Many people wear footwear, apparel, and athletic and protective gear and expect these articles of wear to provide traction and stability during use. For example, articles of footwear may include traction elements that are attached to a sole structure that forms the ground-contact surface of the article of footwear. The traction elements provide gripping characteristics that help create supportive and secure contact between the wearer's foot and the ground. These traction elements typically increase the surface area of the ground-contact surface of the footwear and often form protrusions that are usually shaped to pierce the ground and/or create friction between the ground-contact surface of the footwear and the ground or surface that it contacts.
Conventionally, these traction elements are static with respect to the article of footwear. This means that the traction elements and the footwear move as a single unit, i.e., the traction elements remain stationary with respect to other portions of the footwear and/or its sole structure. The fraction elements progress through the bending and flexing motions of the step or run cycle in the same way as the rest of the footwear.
Athletes engaged in certain sports, such as soccer, baseball, and football, often utilize footwear having traction elements. These athletes perform various movements that have sudden starts, stops, twisting, and turning. Additionally, most athletes wish to wear their articles of footwear in various environments with surfaces having different conditions and characteristics. Static traction elements provide the same type of traction during all movements and in all environments, regardless of the type of movement being performed by the athlete or the characteristics of the environment in which the articles of footwear are being worn.
Additionally, some movements that wearers perform are not able to engage the static traction elements and some surfaces have characteristics that make engaging the static traction elements difficult. The wearer will progress through a step cycle or run cycle that flexes various portions of the article of footwear. Throughout the step or run cycle various portions of the footwear are engaged with the ground or surface while other portions of the footwear are suspended from the ground or surface. Most traction elements are static and move as a single unit with the article of footwear as the wearer goes through the step or run cycle. Oftentimes, various movements in which only a portion of the article of footwear is engaged with the ground or surface may not be provided with the additional traction that the static traction elements provide. Further, various surfaces on which the athlete wishes to wear their articles of footwear have different characteristics including different hardnesses and contours, which can be difficult for at least some static traction elements to engage.
Therefore, while some traction elements are currently available, there is room for improvement in this art. For example, an article of footwear wear having traction elements that may be selectively engageable to provide a user with additional traction during specific motions and on varying surfaces, while remaining comfortable and flexible for the user would be a desirable advancement in the art. Additionally, traction elements that protect against wear and that dynamically engage with a surface in response to a specific application of force, often relating to a targeted motion or a changing characteristic of the surface, would also be a welcomed advancement in the art.